1. Field of Invention
The invention relates to a method for manufacturing a ceramic glow pin which has more than two layers.
2. Description of Related Art
Ceramic glow pins, which are used, ready-manufactured, as glow plugs in the area of internal combustion engines, are characterised in that they can be heated up more quickly than the steel glow plugs used hitherto and have a far longer life.
Already known from U.S. Pat. No. 6,309,589 and German Patent Application DE 100 53 327 A1 (corresponding to U.S. Pat. No. 6,710,305), are ceramic glow pins with planar structures which are designed from manufacturing points of view, so that a homogeneous temperature distribution required for optimum combustion is not ensured.
Furthermore, known from U.S. Pat. No. 6,184,497 B1, EP 0 601 727 B1, U.S. Pat. No. 6,084,212 A, German Patent DE 36 21 216 C1 (corresponding to U.S. Pat. No. 4,742,209), DE 198 44 347 A1 (corresponding to U.S. Pat. No. 6,621,196) and German Patent DE 101 55 203 C1 are designs and methods of manufacture for ceramic glow pins in which layer structures are provided which can only be manufactured by slip casting methods which are difficult to automate in the given layer thickness or are structures which can only be implemented by expensive methods of manufacture which are thus associated with high costs, such as screen printing on laminates followed by hot pressing, for example. These designs and methods of manufacture are difficult to implement on an industrial scale and do not meet the demand of the car industry for inexpensive components.